What are types of Corrosion Inhibitor (Filmer) and neutralizing amine used in crude distillation units. What is the philosophy of their work and the concentration of injection?Nov-2023
Joan de la Paz, Baker Hughes, email@example.com
Corrosion Inhibitor protection mechanisms are the formation of a protective layer between the bare metal and the fluid to minimize the corrosion reaction. there are several chemistries and also can be water or oil soluble. Is really important to have a preliminary survey of the unit before starting a treatment Also is important in the final efficiency of the treatment how this CI is applied. regarding the neutralizing amines the target is to react with the HCL formed at the very initial Dew Point and help to keep the pH at the accumulator in the range of 5.5-6. all chemistries are amine based but there are many composition then also a survey of the unit and process conditions is needed in order to minimize the Salt formation risk.
Marcio Wagner da Silva, Petrobras, firstname.lastname@example.org
According to the characteristics of the processed crude, the performance of desalters needs to be optimized, especially considering the concentration of magnesium and calcium chloride salts which tends to suffer hydrolysis and generate HCl which will concentrates in the overhead system of the atmospheric column, this is a special concern to refiners processing heavy crudes, slop blended with crude oil, and opportunity crudes.
Some refiners adopt an online injection of corrosion inhibitor in the overhead systems to control the salts precipitation. Normally, the corrosion inhibitor applied is a kind of filmic amine like alkylene polyamines (ethylene diamine - EDA, for example) which produces a protective film inside of the critical areas of the atmospheric column and neutralize the acid affect of decomposed salts from the crude oil.
Regarding the concentration of the corrosion inhibitor this vary case by case due to the characteristics of the processed crude, crude oils with high contaminants content and poor desalting performance like heavy and slop crudes tends to present higher concentration of NH3, HCl and amines in the desalted crude oil which raises the probability of corrosion and demands higher flow rates of corrosion inhibitor, it's recommended to look for specialized advice from a chemical treating company which will optimize the system to control de corrosion process under minimum flow rate of corrosion inhibitor as well as indicate what is the best corrosion inhibitor for your processed crude oil blend.